Is CPU bottlenecking?

In some games it may not perform that well but in most cases the Q9400 would be fast enough and handle the CPU load for the GTX 750 ti. the Core 2 Quad Architecture makes it not a true quad core by design. It is basically running 2 core 2 dies on on Chip making i a MCP(multi-chip processor) Games that take advantage of multiple cores like BF3 would fair just fine but Games that require more raw single-threaded power would not

EDIT. In short. the Q9400 even at stock speeds is fine to use with the GTX 750 ti.. I used a C2Q Q6600 / Radeon HD 6870 and BF3 and BFBC2 ran quite well at 1920x1080. And the HD 6870 is still a half decent GPU. Though your GTX 750 ti is a slightly better performer it is not going to need the bleeding edge CPUs to game with,
 


Depending on what you are trying to run. I supose its about gaming since you have decent card from the current gen. Also I supose on this card you are trying to play the most modern games on the best graphics settings possible while maintaining nice fps. Without knowing more about your rig- RAM, PSU, MB and so on I will say the following - q9400 is a quad core CPU but if iam not mistaken its from 2008. 4 real cores at 2.66GHz and 6MB L2 cache. Its not bad but for modern games isnt enough. SO yes i think your CPU is bottlenecking. Also how much RAM do you have, what type and in what channel - single, dual or what? That also could be a problem.
 


6G RAM and 450 PSU
 
The term "bottleneck" is being over-used.

The only time you would actually cpu bottleneck was if you were using a processor weaker than and Dual core Pentium(45nm). Yes, upgrading(maybe to i5-3570k) might boost your performace by like 2-5 max fps but if you were to ask me, it's not worth it. You are NOT bottlenecking.

Feel free to correct me...
 
I don't think it would be your CPU my mums husband has that CPU and a GTX 660ti and not once on any agme thats been played on there has there been any form of bottleneck from CPU or GPU...are you getting high temperatures as that sometimes causes issues!